Following 10 months inside, the joeys are beginning to emerge to become familiar with the outdoors.

Zoo officials say the joeys are averaging roughly five pounds each, and are getting too big to stay inside mom's pouch for much longer.

"There's just too much baby there and not enough room. So what we've been seeing is the baby will get out and try to jump in with the other mother and visa versa. They will share the care of the baby for a short period of time," says Dave Orndorff, Animal Curator with the Ross Park Zoo.

The cycle could continue, zoo officials say. As soon as the joeys are able to leave the pouch, the mothers could be pregnant again.

Zoo officials won't know this for sure until the joeys leave the pouch for good.

The zoo's Facebook page allows visitors to observe the joeys' progress. Just search Binghamton Zoo at Ross Park for pictures and updates.